Building Engineering HVAC and Building Mechanical Systems 2 — Questions and Answers
Question 1: What is the purpose of a building automation system (BAS) in HVAC operations?
- To centrally monitor and control all mechanical and electrical building systems (Correct answer)
- To replace individual thermostats in each zone
- To automate only lighting controls
- To manage only the building's fire suppression system
Correct answer: To centrally monitor and control all mechanical and electrical building systems
A BAS integrates HVAC, lighting, fire safety, and other systems onto one platform for centralized monitoring, scheduling, and energy optimization.
Question 2: Which type of pump is most commonly used to circulate chilled water and hot water in HVAC hydronic systems?
- Centrifugal pump (Correct answer)
- Positive displacement pump
- Peristaltic pump
- Diaphragm pump
Correct answer: Centrifugal pump
Centrifugal pumps are standard in hydronic HVAC systems due to their simplicity, reliability, and suitability for continuous variable-flow operation.
Question 3: What is the primary purpose of a cooling tower in a central HVAC plant?
- To reject condenser heat from chillers to the atmosphere (Correct answer)
- To supply chilled water to air handlers
- To heat water for domestic hot water systems
- To cool outdoor air before it enters the building
Correct answer: To reject condenser heat from chillers to the atmosphere
A cooling tower uses evaporative cooling to dissipate the heat removed from the building by the chiller's refrigeration cycle into the outdoor air.
Question 4: What does SEER measure for residential and light commercial HVAC equipment?
- Seasonal Energy Efficiency Ratio — cooling efficiency over an entire season (Correct answer)
- Static efficiency and energy recovery
- System energy effectiveness rating
- Sensible energy efficiency ratio
Correct answer: Seasonal Energy Efficiency Ratio — cooling efficiency over an entire season
SEER measures the total cooling output divided by total electrical energy input over a typical cooling season, with higher values indicating greater efficiency.
Question 5: What type of HVAC system delivers both heating and cooling through a single piping loop using a heat pump?
- Water-source heat pump system (Correct answer)
- Two-pipe fan coil system
- Variable refrigerant flow system
- Chilled beam system
Correct answer: Water-source heat pump system
Water-source heat pump systems use a common water loop where units can simultaneously heat some zones by extracting heat added by cooling units in other zones.
Question 6: What is the purpose of minimum outside air requirements in HVAC design?
- To dilute indoor contaminants and provide oxygen for occupants (Correct answer)
- To pressurize the building against wind infiltration
- To cool the building without mechanical refrigeration
- To reduce humidity in humid climates
Correct answer: To dilute indoor contaminants and provide oxygen for occupants
Minimum outside air ensures that CO2, VOCs, and other indoor-generated contaminants are diluted to acceptable levels for occupant health and comfort.
Building Engineering HVAC and Building Mechanical Systems 2
What is the purpose of a building automation system (BAS) in HVAC operations?